Currently, the organic electroluminescent display (OLED) element have gradually become the mainstream in the display field, because they have the characteristics such as fast response, wide color gamut, super thinness, capability of being flexible and the like, comparing with the traditional liquid crystal display (LCD) element.
The structure of an OLED element mainly comprises a base substrate, and an organic electroluminescent pixel array formed on the base substrate; wherein each organic electroluminescent pixel array comprises an anode and a cathode disposed oppositely, and a light emitting layer between the anode and the cathode. The light emission of the OLED element is achieved by causing electrons generated in the cathode and holes generated in the anode to be recombined in the light emitting layer so as to excite the organic material in the light emitting layer to emit light. However, in an OLED display element, the organic material used for the light emitting layer and the active metal used for the cathode are very sensitive to moisture and oxygen, therefore, OLED elements require higher technical support than other display elements in terms of encapsulation. If the encapsulation of the OLED element is not fast, moisture and oxygen may penetrate inside the display from the surrounding environment, causing the oxidation of the cathode metal and the deterioration of the organic material of the light emitting layer, such that the lifetime of the OLED element is shorten, or it directly causes the fatal damage of the element so as to influence the application thereof.
Currently, in small or middle sized OLED elements, an encapsulating manner of glass cover plate is predominant. For flexible or large sized OLED elements, the current method mainly comprises simply encapsulating the OLED element with a thin film, and then adhering a moisture and oxygen resistant protection film. Moreover, in order to reduce the reflection of the ambient light by the OLED display element which reduces the contrast and visibility of the display, a circular polarizer should also be adhered after the adhesion of the moisture and oxygen resistant film. The structural schematic diagram is shown by FIG. 1, comprising a base substrate 1, an organic electroluminescent pixel array 2, an encapsulating thin film 3, a moisture and oxygen resistant protection film 4, and a circular polarizer 5.
As seen from the above, the current encapsulating method for a flexible or a large sized OLED element requires a duple film adhering, which may bring the problems such as complicated process, increased cost, and the duple film adhering may also increase the thickness of the flexible element, resulting in the problem of the difficulty in rolling.